IMAGING OXYGEN-TENSION IN LIVER AND SPLEEN BY F-19 NMR

F-19 NMR imaging of the perfluorocarbon emulsion Fluosol(TM) has been used to study regional variations in oxygen tension in rat liver and spleen. We have used the linear dependence of spin lattice relaxation rate (1/T1) on the partial oxygen pressure (PO2) of Fluosol(TM) to determine the oxygen tension in the reticuloendothelial system (RES) of the liver and spleen of male Sprague-Dawley rats which have received serial infusions of Fluosol(TM). Oxygen tension maps have been computed from F-19 NMR images using a calibration obtained for Fluosol(TM) in vitro at 37.5-degrees-C. The spatial resolution of the PO2 maps computed using this technique is 1.2 x 1.2 mm in 3-mm thick slices. Calculations from in vivo pO2 maps indicate an average change in the median pO2 of the RES from 118 to 80 mmHg for (n = 7) rats breathing 95% O2 and 5% CO2 (carbogen) and air, respectively.